1. Field of the Invention
This invention relates to heavy duty power operated blind rivet tools which have a system for collecting the pulled (spent) mandrel of the rivet. More specifically, the invention relates to a control valve for such a mandrel collection system.
2. Summary of the Prior Art
Power operated blind rivet application tools are for heavy duty continuous assembly line operation, and examples of such tools are illustrated in U.S. patent application No. 3,088,618 and 3,254,522.
In the use of such tools, it is desirable to provide a means to quickly and efficiently remove the spent mandrel from the rivet mandrel removing jaw area of the tool. Otherwise, the spent mandrel would have to be removed through the nose of the tool which would prevent quickly inserting into the tool nose another rivet - mandrel assembly for application of the rivet to the workpiece.
Therefore, provision has been made for providing a canister on the rear of the tool and by placing a vacuum in the canister, the spent mandrel is drawn through the tool into the canister. An example of tools with mandrel collection systems of this type are illustrated in U.S. Pat. Nos. 3,415,102 and 4,281,531.
One manner of providing a vacuum in the canister is by supplying air pressure to a transducer coacting with the canister which creates a vacuum in the canister to draw the spent mandrel through the tool. In commonly owned U.S. patent application Ser. No. 506,659 filed June 22, 1983 there is illustrated a mandrel collection system of this latter type.
In some tools, it is desirable to eliminate the function of the mandrel collection system when removing the canister and thus it becomes necessary to render the air line to the collection system inoperative. Otherwise, the spent mandrel would be freely ejected from the rear of the tool with above normal ejection velocity creating a discomfort to the operator. Further, air can be conserved by shutting off the mandrel collection system during break periods.
Heretofore, it has been unknown in this art to provide the air line to a mandrel collection system with a control valve to render the system inoperative with the control valve being located within the physical confines of the tool.